Oki 3320, 3321 specifications Figure C-3-5

2In receiving by serial interface, printing data is omitted or printing operation is not performed.

Are RxD and SSD of Q3 as specified in Figure C-3-4?

No Replace the Q2.

Yes Are, WR, and BUS signals of Q3 pin 3 as specified in Figure C-3-5?

542ns

WR

Q3-3

5V

0V

5V

0V

		Figure C-3-5
No	Replace the Q3.
Yes	Is the level of a BUS signals at Q7 pins 2-9 the same as that of DB0-7 when
	WR	signal is started?
No	Replace the Q7.
Yes	Is 4 pin of Q6 identical to			signal in Figure C-3-5?
			WR
No	Replace the Q6.
Yes	Check Q501 in the SDDV PCB.

C – 10